An instrument able to image conducting surfaces to atomic accuracy; has been used to pin molecules to a surface.
A device in which a sharp conductive tip is moved across a conductive surface close enough to permit a substantial tunneling current (typically a nanometer or less). In a common mode of operation, the voltage is kept constant and the current is monitored and kept constant by controlling the height of the tip above the surface; the result, under favorable conditions, is an atomic-resolution map of the surface reflecting a combination of topography and electronic properties. The STM has been used to manipulate atoms and molecules on surfaces.
A type of microscope that tunnels into a surface being examined using a sharp conductive tip.
A high-resolution imaging instrument that can detect and measure the positions of individual atoms on the surface of a material. A very fine conductive probe is placed at a distance of 10 to 20 A above the surface of a conductive sample, and a bias voltage is applied between probe and surface during scanning, creating overlapping electron clouds and electrons that tunnel between the potential barrier between the probe and the sample. The probe tip is maintained at a constant distance from the sample by a piezoelectric transducer, yielding a three-dimensional topographical image. See Nanolithography.
one of the class of scanning probe microscopes which uses a relatively small wire in very close proximity to a sample surface with a small electrical potential difference causing electrons to jump across the gap (tunneling current), the wire is moved vertically as it scans across the surface to maintain a constant tunneling current, the vertical motion is mapped to provide an indication of the electrochemistry of the surface
The scanning tunneling microscope is used to examine electrically conducting materials. A quantum-mechanical effect occurs between the metal tip of the microscope and the sample. Even though the tip of the microscope and the sample are separated by the tiniest of distances, a measurable current flows – some of the electrons “tunnel†through these electrically isolated barriers. Depending on the distance, the tunneling current is larger or smaller. When the distance between the tip and the sample is very small, the resolution is very high.
A scanning probe microscopy instrument capable of revealing the structure of samples. The STM uses a sharp metal tip positioned over a conducting substrate with a small potential difference applied between them. The gap between the tip and substrate surface is small enough so that electrons can tunnel between the tip and the surface. The tip is then scanned across the surface and adjusted to keep a contact current flowing. By recording the tip height at each location a "map" of the sample surface is obtained.
One type of atomic resolution microscope in which electrons "tunnel" between the microscopes superfine tip and the surface, making possible the construction of atomic or molecular landscapes.
The scanning tunneling microscope (STM) is a non-optical microscope that scans an electrical probe over a surface to be imaged to detect a weak electric current flowing between the tip and the surface. The STM (not to be confused with the scanning electron microscope) was invented in 1981 by Gerd Binnig and Heinrich Rohrer of IBM's Zurich Lab in Switzerland. Although initially greeted with some scepticism by materials scientists, the invention garnered the two a Nobel Prize in Physics (1986).
